1. Field of the Invention
The present invention relates to an ink film holding device and an ink film reel that can be suitably implemented in a line printer-type thermal transfer printing apparatus mounted to a communications apparatus and an information processing apparatus having an image printing function, such as a facsimile, a printer or a copier.
2. Description of the Related Art
FIG. 8 is an exploded perspective view showing a conventional art ink film holding device 1. This holding device 1 includes a supply reel 3 around which an ink film 2 is wound, a first supporting member 4 fitted to one axial end of the supply reel 3, a second supporting member 5 fitted to the other axial end of the supply reel 3, a winding reel 6 that is arranged parallel to the supply reel 3 and around which the ink film 2 is wound that is unwound from the supply reel 3, a third supporting member 7 fitted to one axial end of the winding reel 6, a fourth supporting member 8 fitted to the other axial end of the winding reel 6, and a rotation driving source 9 that rotates the third supporting member 7 around its axis in a pre-determined winding direction A.
The first supporting member 4 includes a right cylindrical portion 11, a ring-shaped flange 12 that is fastened to an intermediate portion between the two ends of the right cylindrical portion 11, and a gear wheel 13 fastened to one axial end of the cylindrical portion 11. The second supporting member includes a right cylindrical portion 15, and a ring-shaped flange 16 that is fastened to an intermediate portion between the two ends of the right cylindrical portion 15. The third supporting member 7 includes a right cylindrical portion 18, and a ring-shaped flange 19 that is fastened to an intermediate portion between the two ends of the right cylindrical portion 18. The fourth supporting member 8 includes a right cylindrical portion 21, a ring-shaped flange 22 that is fastened to an intermediate portion between the two ends of the right cylindrical portion 21, and a gear wheel 23 fastened to one axial end of the cylindrical portion 21.
The gear wheel 23 of the fourth supporting member 8 meshes with a gear wheel (not shown in the drawing) of the rotation driving source 9, which is configured so as to rotate the winding reel 6 in a winding direction A in synchronization with the printing speed, winding the ink film 2 that has been drawn out and transferred from the supply reel 3. The gear wheel 13 of the first supporting member 4 meshes with a gear wheel 35 of a back tension mechanism (not shown in the drawings), which applies a certain tension on the ink film 2 during the printing, and prevents slack or wrinkles in the ink film 2.
The supply reel 3 and the winding reel 6 are arranged in parallel at a certain spacing to one another, and side plates 25 and 26 are arranged at right angles to their axes on both sides in axial direction of the supply reel 3 and the winding reel 6. Substantially U-shaped cutouts 27 to 30 that are open to the top (upward direction in FIG. 8) are formed in the side plates 25 and 26. The cylindrical portions 11, 15, 18 and 21 of the first to fourth supporting members 4, 5, 7 and 8 are fitted detachably into these cutouts 27 to 30.
The portions of the cylindrical portions 11, 15, 18 and 21 protruding inward from opposing inner walls of the side plates 25 and 26 are fitted into the axial ends of the supply reel 3 and the winding reel 6. In this situation, the flanges 12, 16, 19 and 22 of the first to fourth supporting members 4, 5, 7 and 8 are supported by outward-facing outer walls of the side plates 25 and 26. The first and second supporting members 4 and 5 are arranged on a common axis with the supply reel 3 and rotatably support the supply reel 3 around which the ink film 2 is wound. The third and fourth supporting members 7 and 8 are arranged on a common axis with the winding reel 6 and rotatably support the winding reel 6 around which the ink film 2 is wound.
Such a holding device 1 can be installed in a line printer-type thermal transfer printing apparatus mounted to a communications apparatus, such as a facsimile, or an information processing apparatus, such as a printer or a copier, which have an image printing function.
Another example of conventional technology is disclosed in Japanese Unexamined Patent Publication JP-A 11-208049 (1999). In this conventional technology, the holding device includes two side plates, a supply reel around which an ink film is wound, a winding reel winding the ink film guided to it from the supply reel, four supporting members mounted to the respective two axial ends of the supply reel and the winding reel, and two side plates holding the supporting members mounted to the respective two axial ends of the supply reel and the winding reel. The supporting members are arranged on the opposing inner sides of the two side plates, and the holding device has an integrated structure, in which the supporting members do not protrude from the outer side walls of the side plates, thereby making it possible to make the holding device smaller and facilitating the task of exchanging the ink film.
Yet another example of conventional technology is disclosed in Japanese Unexamined Patent Publication JP-A 11-208050 (1999). In this conventional technology, the holding device includes two side plates, a supply reel around which an ink film is wound, a winding reel winding the ink film guided to it from the supply reel, four supporting members mounted to the respective two axial ends of the supply reel and the winding reel, and two side plates holding the supporting members mounted to the respective two axial ends of the supply reel and the winding reel. Two of the four supporting members that are provided with gear wheels and are arranged on one side are tiltably attached to one side plate, sandwiching this side plate with the gear wheels and with flanges. Thus, only the supporting members mounted to the other side plate have to be removed when exchanging the ink film, so that the task of detaching and attaching the supply reel and the winding reel can be facilitated.
In the conventional technology shown in FIG. 8, the task of detaching and the task of attaching the first to fourth supporting members 4, 5, 7 and 8 when exchanging the ink film has to be carried out at a total of four locations, namely the two axial ends of the supply reel 3 and the two axial ends of the winding reel 6, so that there is the problem that these tasks take considerable time, and the workability of the ink film exchange is poor. Furthermore, according to this conventional technology, the body of an apparatus on which the ink film holding device is mounted is provided with a rotation driving source 9 as a mechanism for applying back tension to the first supporting member on the supply reel side, so that there is the problem that the number of components is large, and the apparatus becomes larger because the space taken up by these components in the apparatus body is large.
Furthermore, in the conventional technology disclosed in JP-A 11-208049, the holding device has an integrated structure in which the supporting members are provided on the side plates, so that when changing the ink film, the supporting members mounted to the side of the one axial end of the supply reel and the winding reel and the supporting members mounted to the side of the other axial end of the supply reel and the winding reel are mounted to the respective side plates, so that it is necessary to carry out the tasks of detaching them from the supply reel and the winding reel and then attaching them again. During these tasks, the side plates and the supporting members have to be held simultaneously with one hand, so that there is the problem that the operability is poor, and the exchanging of the ink film takes considerable time. Also in this conventional technology, as shown in the conventional technology shown in FIG. 8, the number of components is large, because the apparatus body has to be provided with a back tension mechanism, and since it takes up space in the apparatus body, there is the problem that the apparatus becomes larger.
Moreover, in the conventional technology shown in JP-A 11-208050, the two supporting members mounted to the one axial ends of the supply reel and the winding reel are provided on one side plate, so that when exchanging the ink film, even though it is not necessary to detach the supporting members arranged on the side of the one axial end from the supply reel and the winding reel and then to attach them again, these supporting members are attached in a loose and tiltable fashion to the side plate, so that when attaching them, the supporting members that are not attached firmly to the side plate have to be mounted while holding the supply reel and the winding reel, precisely positioning their axial orientations. Thus, there is the problem is that the operability is poor, and the exchanging of the ink film takes considerable time. Also in this conventional technology, as in the conventional technologies shown in FIG. 8 and in JP-A 11-208049, the number of components is large, because the apparatus body has to be provided with a back tension mechanism, and since it takes up space in the apparatus body, there is the problem that the apparatus becomes larger.
In the conventional technologies in FIG. 8, in JP-A 11-208049, and in JP-A 11-208050, the supply reel and the winding reel are roughly of right cylindrical shape, and the supporting members include a cylindrical fitting portion fitting into the respective two axial ends of the supply reel and the winding reel, a flange abutting against the end faces of the axial ends of the supply reel and the winding reel, and a bearing supported by the side plate.
With such supporting members, both axial ends of the supply reel and the winding reel are supported rotatably by the side plates, so that between the side plates and the end faces of both axial ends of the supply reel as well as between the side plates and the end faces of both axial ends of the winding reel, there are the flanges and small gaps of a size allowing rotation of the supply reel and the winding reel. This configuration determines the spacing between the side plates and the apparatus body, so that sufficient space has to be ensured in the apparatus body, so that the side plates can be arranged at that distance, and there is the problem that the apparatus cannot be made smaller.
It is an object of the invention to provide an ink film holding device and an ink film reel which allow improvement of the workability of exchanging the ink film and the downsizing of an apparatus on which the ink film holding device is mounted.
The invention provides an ink film holding device comprising:
a supply reel around which an ink film is wound;
a first supporting member that is mounted detachably to one axial end of the supply reel and includes a rotating portion that is fitted to the one axial end of the supply reel and generates a braking force with respect to rotation around the axis of the supply reel;
a second supporting member that is mounted detachably to the other axial end of the supply reel, for supporting the other axial end of the supply reel such that the other axial end is rotatable about the axis of the supply reel;
a winding reel that is arranged parallel to the supply reel, for winding up the ink film that is guided to the winding reel from the supply reel;
a third supporting member that is mounted detachably to one axial end of the winding reel and is rotated in a predetermined winding direction;
a fourth supporting member that is mounted detachably to the other axial end of the winding reel, for supporting the other axial end of the winding reel such that the other axial end is rotatable about the axis of the winding reel;
a first side plate for supporting the first supporting member and the third supporting member such that the first and third supporting members are rotatable about their respective axes; and
a second side plate to which the second supporting member and the fourth supporting member are fastened.
In accordance with this invention, the supply reel and the winding reel are arranged in parallel between the first side plate and the second side plate, and the ink film that is wound around the supply reel is collected by being wound around the winding reel. The supply reel and winding reel between the first and second side plates can be replaced by a new supply reel around which a new ink film is wound and a new winding reel around which no ink film is wound.
In this ink film holding device, the first supporting member is mounted to the one axial end of the supply reel, and the second supporting member is mounted to the other axial end of the supply reel. The third supporting member is mounted to the one end of the winding reel, and the fourth supporting member is mounted to the other end of the winding reel. The first supporting member and the third supporting member are supported rotatably about their axes by the first side plate, whereas the second supporting member and the fourth supporting member are fastened to the second side plate.
Consequently, the first supporting member, which is mounted to the one axial end of the supply reel, is rotatably supported by the first side plate, whereas the other axial end of the supply reel is rotatably supported by the second supporting member, thus allowing rotation of the supply reel around its axis. Also, the third supporting member, which is mounted to the one axial end of the winding reel, is rotatably supported by the first side plate, whereas the other axial end of the winding reel is rotatably supported by the fourth supporting member, thus allowing rotation of the winding reel around its axis.
When the third supporting member is rotated in a predetermined winding direction, its rotation is transmitted to the winding reel, which winds up an ink film that is guided to the winding reel from the supply reel, so that the supply wheel follows this rotation due to the tension of the ink film. In this situation, the rotating portion of the first rotating member rotates together with the supply wheel, but a braking force acts on the rotation of this rotating portion, so that the rotation of the supply wheel is braked, whereby a tension is generated in the ink film that is spanned between the supply reel and the winding reel, namely a so-called back tension is applied. Thus, wrinkles or slack in the ink film in the region in which the ink of the ink film is transferred to the paper can be prevented, and printing defects such as displacements or irregularities in the printed image can be prevented.
This braking force on the rotation of the supply reel for applying back tension to the ink film is achieved with the first supporting member, so that it is not necessary to provide the apparatus body of the apparatus on which the holding device is installed with a back tension mechanism for braking the rotation of the supply reel. Consequently, space in the apparatus body is not taken up by such a back tension mechanism, and it is possible to make the apparatus smaller. Furthermore, when the ink film is exchanged, the task of detaching/attaching the other axial end of the supply reel and the second supporting member as well as the task of detaching/attaching the other axial end of the winding reel and the fourth supporting member are simplified compared to the case where the second supporting member and the fourth supporting member are taken off individually, because the second supporting member and the fourth supporting member are fastened to the second side plate, thus making the task of exchanging the ink film easier, and improving the workability of the apparatus.
In the invention it is preferable that the supply reel is provided with a bearing portion that is rotatably supported by the second supporting member and that is located closer to the one axial end of the supply reel than the other axial end of the supply reel.
According to the invention, because the bearing portion on the other axial end of the supply reel, which is supported by the second supporting member, is formed closer to the one axial end than the other axial end, the bearing portion is more receded to the one axial end than the side face of the other axial end of the supply reel, and consequently, the other axial end of the supply reel is supported with the second supporting member being fitted into the other axial end of the supply reel. Thus, the spacing between the end face of the other axial end of the supply reel and the second side plate on which the second supporting member is provided can be reduced by the distance that the bearing portion is receded from the end face of the other axial end of the supply reel toward the one axial end, the second side plate on which the second supporting member is provided can be placed closer to the first side plate, the space taken up by the holding device can be reduced, and an apparatus on which the holding device is installed can be made smaller.
In the invention, it is preferable that the second supporting member is tapered as it protrudes from the second side plate.
According to the invention, because the second supporting member is tapered, the other axial end of the supply reel can be easily mounted to the second supporting member, so that the supply reel can be easily mounted when exchanging the ink film. Furthermore, by making the second supporting member tapered, the bearing portion is supported by the tip of the second supporting member, so that the rotation axis of the supply reel matches the axis of the second supporting member, achieving a smooth rotation of the supply reel, preventing variations in the tension force on the ink film spanned between the supply reel and the winding reel, and decreasing printing defects.
In the invention, it is preferable that the fourth supporting member is tapered as it protrudes from the second side plate.
According to the invention, because the fourth supporting member is tapered, the other axial end of the winding reel can be easily mounted to the fourth supporting member, facilitating the task of mounting the winding reel when exchanging the ink film.
In the invention, it is preferable that an outer diameter of the second supporting member at a fitting position where the second supporting member is completely mounted to the other axial end of the supply reel is different from the outer diameter of the fourth supporting member at a fitting position where the fourth supporting member is completely mounted to the other axial end of the winding reel, and the inner diameter of the other axial end of the supply reel and the inner diameter of the other axial end of the winding reel are formed slightly bigger than the outer diameter of the second supporting member at the supply reel fitting position and the outer diameter of the fourth supporting member at the winding reel fitting position.
According to the invention, the outer diameter of the second supporting member at the supply reel fitting position is different from the outer diameter of the fourth supporting member at the winding reel fitting position, and the inner diameter of the other axial end of the supply reel and the inner diameter of the other axial end of the winding reel are formed slightly bigger than the outer diameter of the second supporting member at the supply reel fitting position and the outer diameter of the fourth supporting member at the winding reel fitting position, so that, even when trying to mount the fourth supporting member to the supply reel or when trying to mount the second supporting member to the winding reel, insertion is impossible or the fitting is too loose. Accordingly the user easily recognizes the false mounting, and loading errors of the supply reel and the winding reel can be prevented.
In the invention, it is preferable that the second side plate is fastened to an apparatus body of an apparatus for printing using the ink film.
According to the invention, the task of detaching/attaching the second and fourth supporting members from/to the supply reel and the winding reel when exchanging the ink film can be omitted, thus decreasing the number of parts that are mounted to or removed from the supply reel and the winding reel when exchanging the ink film, the operation can be simplified, and the workability of the ink film exchange is improved.
In the invention it is preferable that the apparatus body is provided with an openable lid for covering at least a region accommodating the first supporting member, and the lid is provided with an engaging member that rotates the rotating portion of the first supporting member in a predetermined direction unrolling the ink film when opening the lid, and rotates the rotating portion of the first supporting member in a winding direction that is opposite to the unrolling direction when closing the lid.
According to the invention, the lid is provided with an engaging member, so that as a result of opening the lid in the course of exchanging the ink film, the rotating portion of the first supporting member is rotated by the engaging member in an unrolling direction and the ink film that is spanned between the supply reel and the winding reel can be slackened. On the other hand, when the ink film has been exchanged and the lid is closed, the rotating portion of the first supporting member is rotated by the engaging member in a winding direction and a tension can be applied to the ink film that is spanned in a slack state between the supply reel and the winding reel, so that before beginning the next printing operation, wrinkles or slack in the ink film can be prevented.
In the invention it is preferable that the inner diameter of the one axial end of the supply reel is chosen to be larger than the inner diameter of the other axial end of the supply reel.
According to the invention, it is impossible to mount the first supporting member to the other axial end of the supply reel, because the inner diameter of the one axial end of the supply reel is larger than the inner diameter of the other axial end of the supply reel, so that false mounting can be prevented.
In the invention it is preferable that the supply reel and the winding reel are mounted at least to the first side plate together with the first supporting member and the third supporting member and formed in one unit.
According to the invention, the ink film can be exchanged easily and fast, because the supply reel and the winding reel are mounted with the first supporting member and the third supporting member to the first side plate together and formed in one unit.
The invention provides an ink film reel comprising a right cylindrical reel body around which an ink film is wound, two axial ends of the reel body being supported by a supporting member on an apparatus body of an apparatus for printing with the ink film, so as to rotate around an axis of the reel body,
wherein one axial end of the reel body is provided with a bearing portion that is more receded to the other axial end than an end face of the one axial end, and that is supported rotatably about the axis of the reel body by a tip of the supporting member.
According to the invention, because the bearing portion on the other axial end, which is supported by the supporting member of the ink film reel, is formed closer to the one axial end than the other axial end, the bearing portion is more receded to the one axial end than the side face of the other axial end of the ink film reel, and consequently, when the supporting member is fitted into the other axial end of the ink film reel, the other axial end of the ink film reel is supported. Thus, the spacing between the end face of the other axial end of the ink film reel and the side plate on which the supporting member is provided can be reduced by the distance that the bearing portion is receded from the end face of the other axial end of the ink film reel toward the one axial end, the side plates on which supporting member is provided can be placed closer one another, the space taken up by the holding device can be reduced, and an apparatus on which the holding device is installed can be made smaller.
In the invention it is preferable that the ink film reel is made of a thermoplastic synthetic resin.
According to the invention, it is possible to reuse the ink film reel after the ink film has been exchanged, because the ink film reel is made of a thermoplastic synthetic resin, thus improving economic efficiency.